Door closer mechanism



March 12, 1968 M K. KOIVUSALO DOOR CLOSER MECHANISM 2 Sheets-Sheet 1 Filed May 14, 1965 -FIG1 I NV ENTO R:

S B E N 2 & a T gm u L mm MM March 12, 1968 M. K. KOIVUSALO 3,372,427

DOOR CLO SER MECHANISM Filed May 14, 1965 2 Sheets-Sheet 2 cmi ATTQKNEBS United States Patent O 3,372,427 DOOR CLOSER MECHANISM Mauno Kalevi Koivusalo, Yiiopistonkatu 24C 50, Turku, Finland Filed May 14, 1965, Ser. No. 455,691

' 2 Claims. (Cl. 16-68) ABSTRACT OF THE DISCLOSURE A door closer provided with two cylinders and a piston within one cylinder containing a hollow closed space full of hydraulic liquid or other fluid medium. Hence the length of that piston can be utilized for two different purposes and the main pistons of the cylinders may be made shorter with less weakening of the door structure.

This invention relates to a door closer adapted to be fastened, on the one hand, to the 'door and the like and on the other hand, to the doorframe and the like and including means which, when the door is opened will be tensioned to eifect automatic closure of the door upon its release and means which decelerate the closing action.

Door closers having a mechanism secured to the doorframe and under the action of a draw arm fastened to the inside of the door are known. The mechanism itself generally includes a spiral spring of watch spring type which builds up tension when the door is opened but expends it to close the door when the force tending to move the door to open position is released. The mechanism is usually fastened to the top edge or to the side edge of the doorframe on the inside of the door. The mechanism housing is large in size and heavy. It is often in one's way and can cause harm too. Moreover, because it is unsightly in appearance it is not fit for use in up-to-date buildings. Furtherrnore, it is so large in size that it cannot be conoealed in the doorframe or door, as often desired nowadays. In use, these prior art door closers have not always been found satisfactory in that they are either too tight so that great eitort is needed especially from children to open the door, or then they are so lacking in tension that the door is not swung into full closed position.

This invention has for its object to ohviate the aforementioned disadvantages and to provide a door closer which is very etficient, durable in use and inexpensive to make and which, moreover, is small in structure so that it can be installed and completely concealed in the door and/ or doorframe. The invention includes the feature that the tension building closer means and the decelerating check means are installed, both or either one of the two, in the door and in the doorframe or at least in one of the two, and that for interconnecting the means in the door and the means in the doorframe a draw arm is provided to stay at a suitable distance from the hinge axis The force required for closing the door is provided, in this case, -by compression springs mounted within cylinders which in turn may be embedded in the door and/or the doorframe so they are wholly concealed when the door is in closed position. In order that the door closer of the invention will operate when the door is swung through more than 90, to the hinge is connected a guide -bar which gives support to the draw arm of the closer means, said draw arm extending from the door to the doorfrarne and mounted so that always the same moment rod will be used even when the door is capable of swinging more or less, e.g., 180. The springs or spring within the cylinders are mounted so that they will build up tension when the door is moved into open position and to expend that tension when the door is released for moving the door into closed position. For retarding the closing action, at least one of the cylinders includes an arrangement such that the fluid medium contained within the said cylinder is permitted to pass very slowly from the one side of the spring actuated piston to the other side. Because, in fully closing a door, proper closing speed should be provided in the final closing movement of the door, this leakage of fluid medium from the one side of the piston to the other is arranged so that when the door has almost reached its closed position there is a sudden increase in leakage to insure full closure. The guide bar turning about the hinge axis is preferably formed as a T-shaped bar, said bar having its lower end portion mounted on the hinge pin while each of the two ends of the transverse arm carries the respective link of the draw arm parts mounted on the pistons housed in the cylinders. A guide bar of the stated type will keep the moment rod for swinging the door always fairly steady thus rendering it possible to open the door even a The draw arm is formed preferably from two rods carried by the pistons and the guide bar link which is disposed between the said rods. The piston receiving cylinders Will then be at right angles to the hinge axis. These cylinders, however, may also be positioned paraliel with the hinge aXis but then the draw arm parts between the guide bar and the piston must be made from several links because the direction of the draw or pull plane changes. Then too, each of the draw arm links must ibe provided with an assisting support joint said joint having its one end mounted, preferably, on a hinge leaf and its other end connected to the respective draw arm link. The said support joint may be dimensioned and fitted so that the door is held or locked in a prede termined hold-open position from which it can be released by giving the door a push or pull.

For illustrating the invention reference is made to the accompanying drawing wherein FIG. 1 is a sectional View of the door closer mounted on a plane at right angles to the hinge axis. FIG. 2 is a plan view of the door closer positioned substantially paraliel to the hinge aXis, and FIG. 3 is a fragmentary sectional view of the door closer shown in FIG. 2. In all the figures the door closer is shown in the position in which the closer will be in usage when the door is fully opened (180 FIG. 1 shows the door closer positioned at right angles to the hinge axis and behind the hinge leaves so that both the door and the doorframe must be provided with horizontal boreholes for accommodating them and so that the cylinders 8 and 9 may be sunk into the door and the doorrame. Within the cylinder 9 is disposed a compression spring 13 having one end resting on the hinge leaf 1 and the other end on the face of the piston 11. The other end of the piston is linked to the draw arm part 4, the other end of said arm being pivoted to the transverse bar 2 of the guide bar 3 by means of the pivot pin 7. The guide bar itself is connected to the hinge pin 5. The second corresponding draw arm part is similar to part 4 but the said second draw arm has its other end connected to the one end of the piston 30 by means of the pivot pin 31. The compression spring 12 acts on the other end of the piston in manner similar to the spring 13 in the first mentioned cylinder. The action of spring 12 is only, preferably, slightly weaker than that of the spring 13. The piston 30 is provided with a cylindrical bore hole for accommodating the piston 17, said piston having its one end secured to the cylinder bottom 21 and locked thereto with the nut 22 via the piston rod 15. At the other end of the piston 30 there is provided an enlargement so that under the action of spring 12 the piston 30 slowly moves to the left in the figure while the medium (eg. air or oil) slowly leaks past the piston to the rear of the piston and at the final portion of the closing movement said piston will suddenly move to the left in the drawing while the leakage of medium in the space 10 past the piston 17 to the rear of the piston increases. On opening the door, the medium will rapidly pass from the 'ear of the piston 17 to the right in the figure and into the space through the openings 19 otherwise closed by a fiexible spring plate 18. The hollow piston 30 is closed and made fiuid-tight by means of a nut 20 and Washer 16. This is accomplished in that as the door closes the flexible spring valve plate 18 Will close the openings 19 and fluid medium will leak past the piston 17 because there is a certain small play or clear space between that piston and the cylinder wall. At the other end of the cylindrical wall there is provided a conical enlargement wherein the said play grows and the door closes with proper closing speed. As the door is opened fluid medium can pass from one side of the piston 17 to the other also through the openings 19 since the plate 18 is made of flexible material. The interior of the piston 30 is a closed hollow so that to prevent fluid medium leakage, it is necessary to use a Washer 16 between the nut 20 and the piston rod 15.

The door closer shown in FIGS. 2 and 3 is otherwise similar to that of FIG. 1 except that the draw arm 4 in this instance consists of two inter-linked parts pivoted at 32 and additionally supported on the hinge leaf and draw arm by the hinged support joint 23. The draw arms 4 of each cylinder are preferably alike but may differ in structure also. Moreover, the cylinders 8 and 9 are installed in the door and doorframe in parallel with the hinge aXis so the same are located just back of the hinge leaf. Thus both the door and the doorframe must be provided with a groove-like recess for receving them. The hinge leaf 1 has a hole for permitting the turning of the nut 22 and the adjustnent of the closing action due to the movement of the piston 17 without having to dismount the door closer. Naturally the hinge leaves always have holes or slots for the draw arms. By pushing or pulling the door, i.e., by increasing the tension built up by the spring the door is again released from this hold-open position. The cylinders 8 and 9 are adapted to be closed by the hinge leaf in FIG. l but in the Construction of FIGS. 2 and 3 they are adapted to be closed with a suitable cover 24 upon which the one end of the spring 12 may rest. The cylinders themselves may be secured to the hinge leaves, e.g., by screw means and the like. The draw arms may also be made in manner other than here described. So, eg., they may include a plurality of links and may even be totally tor in part of flexible or resilent material. Then too, the support lever may comprise e.g., a roller upon which the resilent draw arm rests.

It is to be understood that the invention is not limited to the hereinabove described embodlments but includes all forms and structures falling within the scope of the following claims.

I claim:

1. A door closer mechanism to be mounted in a door and a doorframe, said mechanism comprising a cylinder, a piston movable within said cylinder, a compression spring enclosing said piston, another cylinder, a hollow piston having an open end and movable within the second-me'ntioned cylinder, the second-mentioned piston being adapted to be filled with a hydraulic and pneumatic medium, a plate closing the open end of the secondmentoned piston, another compression spring enclosing the second-mentioned piston, a third piston fittng in the second-mentioned piston, a piston rod connected with the third piston, means connecting said piston rod with the second-mentioned cylinder, a hinge leaf engaging said cylinders and the ends of said compression springs, arms connected with the first-mentioned cylinder and the second-mentioned cylinder and extending through said hnge leaf, means pivotally connecting said arms with said hinge leaf and valve means connected with the third-mentioned piston.

2. A mechanism in accordance with claim 1 wherein said third piston constitutes a damper cylinder and has an enlarged rear portion.

References Cited UNITED STATES PATENTS 452,744 4/1891 Ball 16-68 467,997 2/1892 Werth et al. 16-70 1,026,155 5/1912 Duggan 16-68 2,808,608 10/1957 O`Hare 16-70 3,161,908 12/1964 Walach 16-52 FOREIGN PATENTS 217,817 5/ 1966 Australia.

BOBBY R. GAY, Primary Exam'ner.- 

